Thanks for the help!
From here it looks like the new infowindow close button is all that is needed. the new window looks really great on a mobile device.
I am working on getting all of my sites ‘responsive’. Mappress (without new infowindow) works great nested within a <div at 100%. There is only 1 problem. On small media the old infowindow can’t be closed with the ‘x’ close button. On my droid (480 px) it seems like the close link area is too small to activate. Also there is, what seems to be a thin sliver of another image attached to the right of the ‘x’ button.
I hope this info helps you or someone in this forum.